var Playground = {
	setResizeFactor: function(resizeFactor) {
		var playground = document.id('playground');
		var size = playground.getSize();
		var height = size.y;
		var width = size.x;
		var offset = {
			top: height * (1 - resizeFactor) / 2,
			left: width * (1 - resizeFactor) / 2
		};
		playground.setStyles({
			'-webkit-transform': 'scale(' + resizeFactor + ')',
			'-moz-transform': 'scale(' + resizeFactor + ')',
			'-ms-transform': 'scale(' + resizeFactor + ')',
			'-o-transform': 'scale(' + resizeFactor + ')',
			transform: 'scale(' + resizeFactor + ')',
			top: -offset.top,
			left: -offset.left
		});
	}
};